I have the following collection
{
"_id" : ObjectId("57315ba4846dd82425ca2408"),
"myarray" : [
{
userId : ObjectId("570ca5e48dbe673802c2d035"),
point : 5
},
{
userId : ObjectId("613ca5e48dbe673802c2d521"),
point : 2
},
]
}
These are my questions
I want to push into myarray if userId doesn't exist, it should be appended to myarray. If userId exists, it should be updated to point.
I found this
db.collection.update({
_id : ObjectId("57315ba4846dd82425ca2408"),
"myarray.userId" : ObjectId("570ca5e48dbe673802c2d035")
}, {
$set: { "myarray.$.point": 10 }
})
But if userId doesn't exist, nothing happens.
and
db.collection.update({
_id : ObjectId("57315ba4846dd82425ca2408")
}, {
$push: {
"myarray": {
userId: ObjectId("570ca5e48dbe673802c2d035"),
point: 10
}
}
})
But if userId object already exists, it will push again.
What is the best way to do this in MongoDB?
Try this
db.collection.update(
{ _id : ObjectId("57315ba4846dd82425ca2408")},
{ $pull: {"myarray.userId": ObjectId("570ca5e48dbe673802c2d035")}}
)
db.collection.update(
{ _id : ObjectId("57315ba4846dd82425ca2408")},
{ $push: {"myarray": {
userId:ObjectId("570ca5e48dbe673802c2d035"),
point: 10
}}
)
Explination:
in the first statment $pull removes the element with userId= ObjectId("570ca5e48dbe673802c2d035") from the array on the document where _id = ObjectId("57315ba4846dd82425ca2408")
In the second one $push inserts
this object { userId:ObjectId("570ca5e48dbe673802c2d035"), point: 10 } in the same array.
The accepted answer by Flying Fisher is that the existing record will first be deleted, and then it will be pushed again.
A safer approach (common sense) would be to try to update the record first, and if that did not find a match, insert it, like so:
// first try to overwrite existing value
var result = db.collection.update(
{
_id : ObjectId("57315ba4846dd82425ca2408"),
"myarray.userId": ObjectId("570ca5e48dbe673802c2d035")
},
{
$set: {"myarray.$.point": {point: 10}}
}
);
// you probably need to modify the following if-statement to some async callback
// checking depending on your server-side code and mongodb-driver
if(!result.nMatched)
{
// record not found, so create a new entry
// this can be done using $addToSet:
db.collection.update(
{
_id: ObjectId("57315ba4846dd82425ca2408")
},
{
$addToSet: {
myarray: {
userId: ObjectId("570ca5e48dbe673802c2d035"),
point: 10
}
}
}
);
// OR (the equivalent) using $push:
db.collection.update(
{
_id: ObjectId("57315ba4846dd82425ca2408"),
"myarray.userId": {$ne: ObjectId("570ca5e48dbe673802c2d035"}}
},
{
$push: {
myarray: {
userId: ObjectId("570ca5e48dbe673802c2d035"),
point: 10
}
}
}
);
}
This should also give (common sense, untested) an increase in performance, if in most cases the record already exists, only the first query will be executed.
There is a option called update documents with aggregation pipeline starting from MongoDB v4.2,
check condition $cond if userId in myarray.userId or not
if yes then $map to iterate loop of myarray array and check condition if userId match then merge with new document using $mergeObjects
if no then $concatArrays to concat new object and myarray
let _id = ObjectId("57315ba4846dd82425ca2408");
let updateDoc = {
userId: ObjectId("570ca5e48dbe673802c2d035"),
point: 10
};
db.collection.update(
{ _id: _id },
[{
$set: {
myarray: {
$cond: [
{ $in: [updateDoc.userId, "$myarray.userId"] },
{
$map: {
input: "$myarray",
in: {
$mergeObjects: [
"$$this",
{
$cond: [
{ $eq: ["$$this.userId", updateDoc.userId] },
updateDoc,
{}
]
}
]
}
}
},
{ $concatArrays: ["$myarray", [updateDoc]] }
]
}
}
}]
)
Playground
Unfortunately "upsert" operation is not possible on embedded array. Operators simply do not exist so that this is not possible in a single statement.Hence you must perform two update operations in order to do what you want. Also the order of application for these two updates is important to get desired result.
I haven't found any solutions based on a one atomic query. Instead there are 3 ways based on a sequence of two queries:
always $pull (to remove the item from array), then $push (to add the updated item to array)
db.collection.update(
{ _id : ObjectId("57315ba4846dd82425ca2408")},
{ $pull: {"myarray.userId": ObjectId("570ca5e48dbe673802c2d035")}}
)
db.collection.update(
{ _id : ObjectId("57315ba4846dd82425ca2408")},
{
$push: {
"myarray": {
userId:ObjectId("570ca5e48dbe673802c2d035"),
point: 10
}
}
}
)
try to $set (to update the item in array if exists), then get the result and check if the updating operation successed or if a $push needs (to insert the item)
var result = db.collection.update(
{
_id : ObjectId("57315ba4846dd82425ca2408"),
"myarray.userId": ObjectId("570ca5e48dbe673802c2d035")
},
{
$set: {"myarray.$.point": {point: 10}}
}
);
if(!result.nMatched){
db.collection.update({_id: ObjectId("57315ba4846dd82425ca2408")},
{
$addToSet: {
myarray: {
userId: ObjectId("570ca5e48dbe673802c2d035"),
point: 10
}
}
);
always $addToSet (to add the item if not exists), then always $set to update the item in array
db.collection.update({_id: ObjectId("57315ba4846dd82425ca2408")},
myarray: { $not: { $elemMatch: {userId: ObjectId("570ca5e48dbe673802c2d035")} } } },
{
$addToSet : {
myarray: {
userId: ObjectId("570ca5e48dbe673802c2d035"),
point: 10
}
}
},
{ multi: false, upsert: false});
db.collection.update({
_id: ObjectId("57315ba4846dd82425ca2408"),
"myArray.userId": ObjectId("570ca5e48dbe673802c2d035")
},
{ $set : { myArray.$.point: 10 } },
{ multi: false, upsert: false});
1st and 2nd way are unsafe, so transaction must be established to avoid two concurrent requests could push the same item generating a duplicate.
3rd way is safer. the $addToSet adds only if the item doesn't exist, otherwise nothing happens. In case of two concurrent requests, only one of them adds the missing item to the array.
Possible solution with aggregation pipeline:
db.collection.update(
{ _id },
[
{
$set: {
myarray: { $filter: {
input: '$myarray',
as: 'myarray',
cond: { $ne: ['$$myarray.userId', ObjectId('570ca5e48dbe673802c2d035')] },
} },
},
},
{
$set: {
myarray: {
$concatArrays: [
'$myarray',
[{ userId: ObjectId('570ca5e48dbe673802c2d035'), point: 10 },
],
],
},
},
},
],
);
We use 2 stages:
filter myarray (= remove element if userId exist)
concat filtered myarray with new element;
When you want update or insert value in array try it
Object in db
key:name,
key1:name1,
arr:[
{
val:1,
val2:1
}
]
Query
var query = {
$inc:{
"arr.0.val": 2,
"arr.0.val2": 2
}
}
.updateOne( { "key": name }, query, { upsert: true }
key:name,
key1:name1,
arr:[
{
val:3,
val2:3
}
]
In MongoDB 3.6 it is now possible to upsert elements in an array.
array update and create don't mix in under one query, if you care much about atomicity then there's this solution:
normalise your schema to,
{
"_id" : ObjectId("57315ba4846dd82425ca2408"),
userId : ObjectId("570ca5e48dbe673802c2d035"),
point : 5
}
You could use a variation of the .forEach/.updateOne method I currently use in mongosh CLI to do things like that. In the .forEach, you might be able to set all of your if/then conditions that you mentioned.
Example of .forEach/.updateOne:
let medications = db.medications.aggregate([
{$match: {patient_id: {$exists: true}}}
]).toArray();
medications.forEach(med => {
try {
db.patients.updateOne({patient_id: med.patient_id},
{$push: {medications: med}}
)
} catch {
console.log("Didn't find match for patient_id. Could not add this med to a patient.")
}
})
This may not be the most "MongoDB way" to do it, but it definitely works and gives you the freedom of javascript to do things within the .forEach.
Hi I have the function which get object with id array like this.
{
"participants": [
"5fa566b5b96a9407c804ccd4",
"5fa5639cb96a9407c804ccce"
]
}
And I need to find object which have exactly this fields
Objects in which i try to find it looks like this:
{
"_id" : ObjectId("5fac288e53a6a72e94f721fa"),
"participants" : [
ObjectId("5fa566b5b96a9407c804ccd5"),
ObjectId("5fa5639cb96a9407c804ccc5")
],
"messages" : [],
}
I am trying to do like this but it doesn't work.
async filterDialog(newDialog: any){
const res = await Dialog.find({
'participants': { $in: { ...newDialog.participants } }, function(err: any, dialog: any) {
if (err) {
return err
} else {
return dialog
}
},
})
return res;
}
Will be glad if someone help me.
I think you need $all operator.
Check this query:
db.collection.find({
"participants": {
"$all": yourArray
}
})
Only return the document where the field participants contains all element from the given array.
Example here where I've used numbers instead of ObjectId to read easier.
Please check if this is the behavior you expect.
In MongoDB, this is the simplified structure of my account document:
{
"_id" : ObjectId("5a70a60ca7fbc476caea5e59"),
"templates" : [
{
"name" : "Password Reset",
"content" : "AAAAAAAA"
},
{
"name" : "Welcome Message",
"content" : "BBBBBB"
}
]
}
There's a similar default_templates collection
let accnt = await Account.findOne({ _id: req.account._id }, { templates: 1 });
let defaults = await DefaultTemplate.find({}).lean();
My goal is to find the missing templates under account and grab them from defaults. (a) I need to upsert templates if it doesn't exist in an account and (b) I don't want to update a template if it already exists in an account.
I've tried the following:
if (!accnt.templates || accnt.templates.length < defaults.length) {
const accountTemplates = _.filter(accnt.templates, 'name');
const templateNames = _.map(accountTemplates, 'name');
Account.update({ _id: req.account._id, 'templates.name' : { $nin: templateNames } },
{ '$push': { 'templates': { '$each' : defaults } } }, { 'upsert' : true },
function(err, result) {
Logger.error('error %o', err);
Logger.debug('result %o', result);
}
);
}
This succeeds at the upsert but it will enter all default templates even if there's a matching name in templateNames. I've verified that templateNames array is correct and I've also tried using $addToSet instead of $push, so I must not understand Mongo subdoc queries.
Any ideas on what I'm doing wrong?
Edit: I've gotten this to work by simply removing elements from the defaults array before updating, but I'd still like to know how this could be accomplished with Mongoose.
You can try with bulkWrite operation in mongodb
Account.bulkWrite(
req.body.accountTemplates.map((data) =>
({
updateOne: {
filter: { _id: req.account._id, 'templates.name' : { $ne: data.name } },
update: { $push: { templates: { $each : data } } },
upsert : true
}
})
)
})
I have two Collections Category and Feeds.
Category
{
"_id": "ADFGFDF",
"title" : "title",
}
Feeds
{
"_id": "DFSAHT",
"feeds" : "ds sdsd sds",
"categoryId" : "catId"
}
I need to get the result like this:
{
"_id": "ADFGFDF",
"title" : "title",
"categoryId" : "DFSAHT"
"category" : {
"_id": "DFSAHT",
"feeds" : "ds sdsd sds",
}
}
I tried using publish-composite and here it's my code.
Server
Meteor.publishComposite('feedscateg', function () {
return {
find: function () {
return Category.find({});
},
children: [
{
find: function (cat) {
return Feeds.find({ categoryID: cat._id });
}
}
]
}
});
In client Angular i tried this:
$scope.feeds = $meteor.collection(Category).subscribe('feedscateg');
And I am confused with the view part also.
publishComposite do not modify collection data, it will load Feeds and Category separately. If you want to get category of feed item just select it from client db.
$scope.getFeedCategory = function (feedItem) {
Category.findOne({'_id': feedItem.categoryId});
};
my schema looks like this:
var exampleSchema = newSchema({
profile:{
experience :[{
exp : String
}]
}
});
this is the codes to update experience in profile collection:
exampleSchema.statics.experience = function (id,experience, callback){
var update = {
$push: {
'profile.experience': experience
}
}
this.findByIdAndUpdate(id,update,function(err) {
if (err) {
callback(err);
} else {
callback(null);
}
})
I was getting error like The field 'profile.experience' must be an array but is of type String in document {_id: ObjectId('5653f1d852cf7b4c0bfeb54a')}[object Object]
console.log(experience) is equal to
{ exp: 'jlkjlkjlk' }
my collection should look like this:
experience:[
{
exp : "YYYY"
},
{
exp:"xxxx"}
]
Imagine that you have this collection:
/* 1 */
{
"_id" : ObjectId("565425e862760dfe14339ba8"),
"profile" : {
"experience" : [
{
"exp" : "Experto"
}
]
}
}
/* 2 */
{
"_id" : ObjectId("565425f562760dfe14339ba9"),
"profile" : {
"experience" : {
"exp" : "Experto"
}
}
}
/* 3 */
{
"_id" : ObjectId("5654260662760dfe14339baa"),
"profile" : {
"experience" : "Experto"
}
}
If you try (update doc /* 2 */):
db.profile.update(
{ _id: ObjectId("565425f562760dfe14339ba9") },
{ $push: { "profile.experience" : { exp : "Intermediate" } } }
)
You get this error:
The field 'profile.experience' must be an array but is of type Object
in document {_id: ObjectId('565425f562760dfe14339ba9')}
And if you try (update doc /* 3 */):
db.profile.update(
{ _id: ObjectId("5654260662760dfe14339baa") },
{ $push: { "profile.experience" : { exp : "Intermediate" } } }
)
You will get:
The field 'profile.experience' must be an array but is of type String
in document {_id: ObjectId('5654260662760dfe14339baa')}
i changed Schema like this
experience : [{type:String,exp:String}],
my update object looks like this
var update = {
$push: {
'profile.experience': san.exp
}
};
san looks like this :{ exp: 'YYY' }
Inside mongoose collectionlooks like this used RoboMongo
"experience" : [
"experienced in XXX",
"YYY"
],
$push: {
'profile.experience': experience
}
Remove .exp.
First you have to check you declared your field as an array like this(look at field products):
shop = {
'name': "Apple Store",
'description': "",
'direction': "",
'contact': "",
'products':[]
}
Now if you want to add something to the field products using $push
product = {
'name': "Iphone 6",
'description': "Iphone model 6, 64GB",
'price': 700,
'count': 3
}
myquery = { "name" : "Apple Store" }
obj ={"$push":{"products":{"$each": [product]}}}
db.collection.update_one(myquery,obj)
This code is provided for PyMongo framework. To use in MongoDB directly replace update_one by update. Mongo resource
You may use $set instead of $push which might work.
$set: {
'profile.experience': experience
}
are you searching for adding multiple values into single field then use this one.
write this one your model or schema:
arrayremarks:[{remark: String}]
then write in your controller:
module.exports.addingremarks = (req, res) => {
let casenum=JSON.parse(JSON.stringify(req.body.casenum).replace(/"\s+|\s+"/g,'"'))
var rem={remark:"Suman macha"}
Inwart.update( { 'casenum': casenum },{ $push: { arrayremarks:rem} } ,function (err, inwarts) {
if (err)
return console.error(err);
res.send(inwarts);
}
)
}